皆伐炼山对林地养分元素资源迁移影响的研究

A STUDY OF THE EFFECT OF CLEAR CUTTING AND PRESCRIBED BURNING ON THE MIGRATION OF THE NUTRIENT ELEMENTRESOURCES OF THE FOREST LAND

本文研究了林地皆伐火烧后生物量和养分元素资源迁移状况。结果表明：皆伐后移出林地生物量占林分地上部分总生物量８０％以上，移出林地养分元素Ｃａ、Ｍｇ占林地地上部分Ｃａ、Ｍｇ６０％以上，Ｎ、Ｐ、Ｋ则低于５０％；采伐剩余物在火烧过程中Ｎ损失率高达９５％，Ｐ、Ｋ、Ｃａ、Ｍｇ损失相对较少；火烧后表层土壤Ｎ、Ｐ有一定损失，Ｃａ、Ｋ、Ｍｇ则有所增加。皆伐火烧基本上将整个林分生长期所积累起来的地上部分生物量和养分元素全部迁移出林地。

his paper studies the migration of nutrient element resources of the forest land after clear cutting and prescribed burning. The results are as follows: the biomass that migrates out of the forest land after clear cutting is above 80% of the total biomass of the forest land, the migration of Ca and Mg is above 60%, and the migration of N,P and K is below 50%. The nitrogen loss rate of clearing residue during burning is above 95%, and the loss rates of P,K,Ca and Mg are relatively lower. N and P reserves decrease and Ca,K and Mg increase slightly in the surface soil layer after prescribed burning. Almost all the biomass and nutrient elements of the forest land which accumulate during the whole growth stage of the forest stand are migrated out of the forest land after clear cutting and prescribed burning.